Dominator or HP EFI

[Danny Cabral]

So for my wheel speed sensor, I know it's a 2-wire connection. So do I have to use 2-wires on the I/O cable?

No, just the one signal wire (IPU Speed/Freq) is routed to the I/O Auxiliary Harness.
Dominator Auxiliary Harnesses: https://www.holley.com/products/fuel...efi/harnesses/

To connect up to 4 Inputs & Outputs to the EFI Main Harness, use I/O Auxiliary Harness 558-400.
Eight Wire I/O Auxiliary Harness Connector Pin-Out (also in the Holley EFI Wiring Manual - LINK):
Pin A...A12...White/Blue (Input #1) F,5,2,T,H,G
Pin B...A3....White/Red (Input #2) F,5,2,T,H,G
Pin C...A13...White/Black (Input #3) F,5,G
Pin D...A4....White/Green (Input #4) F,5,G
Pin E...B12...Gray/Yellow (Output #1) H,P+
Pin F...B11...Gray/Red (Output #2) H,P+
Pin G...B10...Gray/Black (Output #3) G,P−
Pin H...B3....Gray/Green (Output #4) G,P−
http://documents.holley.com/199r10516.pdf (Holley 558-400 I/O Auxiliary Harness Instructions)

The 558-400 I/O Auxiliary Harness is 20 feet long.
It's "plug & play" into the main harness, and an easy way to connect common things like an electric cooling fan (LINK).
This I/O Auxiliary Harness isn't required for the optional oil & fuel pressure transducers, which are also "plug & play" into the main harness.
The oil & fuel pressure transducers are used for Data Monitoring, Data Logging and setup Outputs based on oil & fuel pressure.

Or would I just run one to that, and then ground the other cable from the sensor?

Yes, the other wire is grounded.
http://forums.holley.com/showthread....3598#post53598 (Wiring Additional Sensors - HP & Dominator ECUs)

[rand0b]

Awesome. That last LINK looks like the piece I've been looking for! Thanks!

[Danny Cabral]

You're welcome. That page does get a lot of hits.

[Apoc]

I'm naturally aspirated and I'm using 7 Inputs & 12 Outputs. Most people who suspect they'll need more I/O, usually do.

Can you go into a little detail here so that guys like us can further anticipate our needs and not purchase the wrong system? Thank you!

[81 TransAm]

I have a Dominator EFI on a N/A engine. For my inputs I have:
1) A/C Kick
2) ECU Log Trigger
3) Transmission Pressure (Transducer)
4) Crankcase Vacuum (Transducer)
5) 94 Octane, I tuned my engine to run on 89 octane (Knock Sensors). Then I can activate an Timing Advanced Table when I put 94 octane fuel in it.

Outputs:
1) Electric Vacuum Pump for crankcase vacuum.
2) A/C Fans
3) Rad Fans
4) Shift light
5) A/C Pump
6) Knock Sensor Warning Light (LED)
7) Transmission Cooler Fan

Danny, have you looked at the new line of LS Terminator X systems? They really cut the price down on them.

[Danny Cabral]

Danny, have you looked at the new line of LS Terminator X systems? They really cut the price down on them.

Yeah, but it's not a Dominator ECU.

[81 TransAm]

Ya, they look like a light version of the HP & Dominator ECUs.